Olefins, which are important articles of commerce, upon storage and exposure to air tend to form peroxides, hydroperoxides, and other oxidized, unstable materials whose presence can be detected by analytical procedures such as determining the so-called peroxide number. Such peroxidic materials are dangerous in themselves because of their instability, and their presence may even lead to explosions. In addition to posing a safety hazard, build-up of peroxidic materials may render the olefins unsuitable for further use, e.g., as raw materials for sulfonation leading to detergents. Finally, formation of peroxidic materials frequently is associated with a significant undesirable darkening of olefins. The color often is carried along in production of other materials of commerce, and the resulting products are less desirable, and sometimes even unacceptable, because of their darker color. Removal of such color bodies from materials made from darkened olefins is often difficult and expensive, hence there is a necessity for providing olefins as light in color as is possible.
Removal of peroxidic material from alpha-olefins, i.e., linear, unbranched olefins having a terminal methylene group, commonly is performed using a single- or multi-stage wash with sodium bisulfate, or, alternatively, distilling the olefin from sulfuric acid. However, it has been found that neither method is satisfactory to reduce the peroxide number of internal olefins, whether branched or unbranched. It also has been found that unbranched internal olefins form peroxidic materials more readily than alpha-olefins, and branched internal olefins having a tertiary allylic hydrogen atom, i.e., with the structural unit R.sub.1 R.sub.2 CH--C--C--R.sub.3, where R.sub.1 -R.sub.3 are alkyl groups, are still more susceptible to formation of peroxidic materials with concomitant darkening. The internal olefins pose the dilemma of becoming darker and forming peroxidic materials faster than do alpha-olefins, while being more resistant to removal of color bodies and peroxidic materials than is the case for alpha-olefins.